Hydraulic brake



May 3l, 1932. c. WANINGER 1,860,756

HYDRAULIC BRAKE Filed 001;. 29, 1928 F n d 1.9 5

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Patented May 3 1, V1932 UNITED STATES PATENT OFFICE CARL WANINGER, OF DUSSELDORF, GERMANY, ASSIGNOR TO THE FIRM RHEINISCHE METALLWAAREN- UND MASCHINENFABRIK, OF DUSSELDORF-DERENDOBF, GER- MANY,

HYDRAULIC BRAKE Application filed October 29, 1928, Serial No. 315,845, and in Germany/May 16, 1928.

The invention consists in the particular construction of a hydraulic brake 1n wh1ch the openings for the passage of the ,liqu1d in the brake piston are covered by spring hicles, large braking pressures and forces of considerable magnitude are generally concerned; for example in a railway buffer the valve only opens at a pressure of about 400 kilograms per square centimetre and a braking force of about 45 tons can be exerted. In the arrangement-'of the separate valve plates with these loadedn springs, the masses to be moved become so great, that during the braking process they are set into relatively' slow oscillation and, during a complete stroke ofV the brake, the brake pressures and brake farces are very unequal and vary considera ly.

The object of the invention is to remove these disturbing effects by making the valve masses as small as possible, and this is obtained by omitting a special valve member, the valve spring itself acting also as the member closing the apertures for the flow of the liquid. v

If several apertures for the iiow are -provided, each of these can be closed by a separate valve spring; but preferably, all the openings in the piston are closed'by a plate-spring, either a shell shaped plate spring or a plane plate. The surface of the spring plate may lie closely against the openings of the different passages, or open ends of the passages may be connected together by an annular passage arranged close to the elastically lifted edge of the plate spring, so that the hydraulic pressure is effective during the working stroke of the brake immediately over a large surface of the plate. The valve spring is initially stressed to a greater or less extent in dependence on the brake force required, or the force of the spring can be increased steeper characteristic obtained without applying an initial stress. f

The accompanying drawings show in 1ongitudnal section examples of constructions of brake valves according to the invention.

Figure 1 is a cross sectional view of a hydraulic brake in which the piston is stationar` and the cylinder is movable,

igure 2 is a part sectional view of a brake in which the cylinder is stationary and the piston movable,

Figure 3 is a part sectional View of a modilied piston construction, and

-Figure 4 is a cross-sectional view of the cylinder showing the channels of Fig. 2.

Figure 1 illustrates a hydraulic brake for guns in which in known manner the brake cylinder a filled with liquid is rigidly connected by an extension b with the gun barrel (not shown), so that on firing it recoils in the direction shown by the arrow w. The brake `by correspondingly larger dimensions and a piston c is held stationaryby the piston rod l l being connected to a projection e on the bar@ closes the ends of the passages f. The plate spring has, preferably, a pointed surface referring to surface c of the piston so that by screwing up the nut it can be stressed to attain the brake force-required at any time. On the recoil of the barrel after tiring, the elastic perimeter of the plate spring g is raised from its seatc by the liquid pressure in the brake cylinder on the piston Tod side and provides a free path for the liquid from one side to the other of the piston; the brake force depends inthis case on the spring loading of the valve. V

In the construction according toFig. 2, the vertexof the conical plate spring g andthe front surface c are in a direction of the operation of the piston rod, indicated by arrow ai', that is, against the direction of How of the fluid during working stroke. This conicalform of the plate spring can be accomplished either by a tensioning of the plate spring g or it can be originally given a con- 5 ical form, when the force required for chaning the form is already so great for the lifting of the plate spring g from the surface o' of the piston in an untensioned condition that an opening of the passages f and f follows only during a desired brake pressure. Also, the ends of the passages f under the plate spring g are connected to ether by an annular oove f which is rought as close as posslble to the rim of the spring, so that l5 the pressure of the liquid is exerted on the plate spring, not only at-,the ends of the passages, but over the whole annular zone. In Figure 3, the plate spring does not lie directly on the front surface c of the piston and the fends of the passages f. There is a free annular hollow space left which extends from its circular inner edge at the piston rod d to its outer edge which can be raised against ,y its elastic resistance and lies on the piston surface e. In this way, during the working piston stroke, theliquid pressure is immediately effective over 'the whole surface of 'the plate and the brakin pressure and force remain constant after tie plate spring has been lifted, apart from the variable elastic resistance. For theback ow of the liquid from the reservoir space into the pressure .chamber during the return movement of the piston c, in the constructions shown either -return 85 valves c2 in Fi 1 and 3 in thepiston,'or l A channels o in lfisg. 2 slotted in known manner in the walls of the piston or brake cylinder can be utilized.

' I claim: v 40 1. A hydraulic brake comprising a brake cylinder, a piston adapted to slide in said cylinder and having a pair of series of fluid passages therein, one series of passages being adapted to convey the fluid during theworking stroke of the piston and the other for conveying the yHuid during return movement of the piston, and a plate spring valve closing the working stroke series of passages and adapted to open when a specific pressure is -150 applied on the liuid in the cylinder by the piston.

2. A hydraulic brake comprising a brake cylinder, a piston adapted to slide in said cylinder land having a plurality of passages 65 therein, and a plate spring valve closing the passages and having a strength so that the valve will not open to allow assage of iuid until a specific pressure is app ied on the fluid by the plston.

In testimony whereof I have aiixed my signature.

CARL WANINGER. 

